The purpose of the research was to see whether work of special educators and rehabilitators in the regular school has a positive influence on peer relationship among students with delayed cognitive development.The accent was on friendship quality, social competence and antisocial behavior. The research comprised 150 students with slow cognitive development, 52 of who have support of special educators and rehabilitators in regular education, while the remaining 98 students are without support. Friendship quality was evaluated applying Friendship Quality Questionnaire. School Social Behavior Scale was used in order to evaluate social competence and antisocial behavior. Differences among the groups were examined by t-test from SPSS 14 Windows software package.The results have shown that students with slow cognitive development having support from special educators and rehabilitators evaluate their friendship more qualitative. Students with delayed cognitive development attending schools without special educators and rehabilitators engaged demonstrate better level of the social competence. As far as antisocial behavior concerns, no differences were found. The results obtained indicate need for redefining the role of special educators and rehabilitators in regular primary education.